Environment & Energy
Related: About this forumAltamont Pass turbines kill 50% fewer birds
http://fuelfix.com/blog/2013/01/29/altamont-pass-turbines-kill-fewer-birds/SAN FRANCISCO For decades, wind turbines straddling the Altamont Pass have generated clean electricity for California at the cost of killing thousands of birds.
The tall, grassy hills, raked by stiff winds in spring and summer, offer prime hunting territory for owls, hawks and eagles. Focused on spotting prey, many birds soar straight into the spinning blades of turbines.
But efforts to curb the bloodshed may be starting to work.
A new study suggests that the number of eagles, kestrels, burrowing owls and red-tailed hawks killed at Altamont each year has fallen roughly 50 percent since 2005. Reaching that level has been a long-term goal of local environmentalists and government officials, as well as the energy companies running turbines in the pass.
Were pretty pleased with the results, said Sandra Rivera, assistant planning director for Alameda County. Its a fine balance between having the renewables we all want to have in California and keeping the wildlife safe. Thats what weve all been trying to achieve.
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MuseRider
(34,095 posts)I remain a tad bit of a skeptic, I do want this to be true. I wonder from judging what I see out here on my farm as an avid bird watcher if it is because there are 50% fewer birds? This place is becoming dead, I don't know. I hope it is because of their changes.
dbackjon
(6,578 posts)Altamont Pass turbines should have been shutdown and dismantled years ago.
NYC_SKP
(68,644 posts)It is due to replacement of older designs with fewer newer larger slower spinning turbines.
Wind rocks....
.
dbackjon
(6,578 posts)From birders I know in the Bay Area, Owls are down in number in the region.
dbackjon
(6,578 posts)And while bird deaths appear to be dropping, they wont end altogether. The local population of golden eagles already has shrunk so much that it may not survive long term, said Doug Bell, wildlife program manager for the East Bay Regional Park District.
Altamont Pass should be eliminated as a wind site.
NYC_SKP
(68,644 posts)I think I've met Doug Bell.
I should give him a call.
dbackjon
(6,578 posts)But if population has crashed, it is logical that deaths by the wind farms would drop, since there are few if any Golden Eagles in the area to be killed by the wind farms.
Blind support of all wind farms accomplishes nothing.
There are places where wind farms can have minimal impact on the avian and bat population. Altamont Pass is not one of them.
NYC_SKP
(68,644 posts)The Altamont is not ideal because the geography of it is such that it's a bit of a corridor for both wind and avian life.
I addressed the fact that changes in the technology have had a positive impact.
Am I wrong?
I did not say that Altamont wind is awesome, I said that wind rocks.
dbackjon
(6,578 posts)Wind Rocks is a blind support statement.
NYC_SKP
(68,644 posts)....someone who likes to post things in their subject line about other poster's messages that aren't factually true.
Why would you do that?
FBaggins
(26,714 posts)Replacement of older designs was part of it... but it was also turning turbines off during the winter months.
Not exactly an endorsement for "wind rocks"... particularly when you consider that these are the times when solar power is also at its nadir.
Nihil
(13,508 posts)> but it was also turning turbines off during the winter months.
All they need to do is turn off the turbines for the remaining months and they'll be able to
claim that bird mortality has been reduced by almost 100% thus proving that it is the
most bird-friendly source of energy in ... oh, wait ...
There are multiple components to why we get bird kills.
First - just putting up the towers kill birds. Birds fly into static towers both wind turbine towers and power line towers. When birds are zeroing in on prey on the ground, they aren't looking out for obstacles in their flight path very well.
Stopping the blades helps; but even stopped blades on static towers kill birds.
The new designs have slower angular velocity; but since they are taller with longer blades; the tip velocity of the new turbines is actually faster than the tip velocity of the old turbines.
It just looks slower since humans judge speed by the angular velocity and not the translational velocity.
PamW
I live in Livermore, California. I can see the Altamont wind farm from my house.
They measured fall in the bird deaths is NOT due to the newer designs.
Yes - the Altamont is replacing the old turbines with new turbines that are larger and slower moving. However, there are only a couple of the new turbines in operation.
The reason the bird deaths are down is due to the dismantlement of the old turbines in preparation for the new turbines. The fall in bird deaths didn't begin when the old turbines were stopped; the fall in bird deaths began when the old turbines were dismantled.
It's a myth that the birds are only killed by spinning blades. The birds fly into towers. There are just as many dead birds around the power lines that traverse the region as there are in the wind farm proper.
The raptors and eagles that inhabit the area are just poor pilots. When they zero in on some rodent or rabbit that is near the wind turbine tower, their entire attention is on the prey and they end up flying into towers rather than flying into blades.
It's really the static towers and not moving blades that are responsible for the majority of the bird kills.
That's why the bird kill didn't drop when the brakes where set on the turbines.
It's only when they dismantled the towers that we got fewer bird kills.
http://www.sfgate.com/business/article/Altamont-Pass-turbines-kill-fewer-birds-4230640.php
Right now; we have fewer towers in the windfarm since the old turbines have been dismantled and the new turbines are just now being erected to replace them.
That's why, as the article states, the bird advocates aren't claiming victory yet. They want to wait and see what happens when more of the new turbines are up.
Although the angular turn rate of the new turbines is slower; what counts is not the angular velocity but translational velocity of the blades. The new turbines have longer blades; so even though the angular turn rate is slower, the blade tips are actually moving faster with the new turbines.
PamW
PamW
(1,825 posts)The birds are NOT thriving in the Altamont.
The Altamont wind farm has been killing birds for decades; and the population of birds in the Altamont is down SEVERELY.
I noted that the article just gave raw numbers - the number of kills.
It would be more informative if the article gave number of kills per unit population of birds.
If an area had 1,000 birds and 10 bird deaths per year; that's a 1% kill rate.
After many, many years let's say the area has 500 birds, and 5 bird deaths per year. That's still 1%.
However, the 5 deaths per year is half of the old number 10; so someone can claim 50% reduction.
It's still a 1% kill rate; but the number of kills are down since the population is down.
Birds are NOT thriving in the Altamont.
PamW